/*
 * C utilities
 *
 * Copyright (c) 2017 Fabrice Bellard
 * Copyright (c) 2018 Charlie Gordon
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

// Copyright 2024 The Lynx Authors. All rights reserved.
// Licensed under the Apache License Version 2.0 that can be found in the
// LICENSE file in the root directory of this source tree.

#ifdef __cplusplus
extern "C" {
#endif
#include "quickjs/include/cutils.h"
#ifdef __cplusplus
}
#endif

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wconversion"

void pstrcpy(char *buf, int buf_size, const char *str) {
  int c;
  char *q = buf;

  if (buf_size <= 0) return;

  for (;;) {
    c = *str++;
    if (c == 0 || q >= buf + buf_size - 1) break;
    *q++ = c;
  }
  *q = '\0';
}

/* strcat and truncate. */
char *pstrcat(char *buf, int buf_size, const char *s) {
  int len;
  len = strlen(buf);
  if (len < buf_size) pstrcpy(buf + len, buf_size - len, s);
  return buf;
}

int strstart(const char *str, const char *val, const char **ptr) {
  const char *p, *q;
  p = str;
  q = val;
  while (*q != '\0') {
    if (*p != *q) return 0;
    p++;
    q++;
  }
  if (ptr) *ptr = p;
  return 1;
}

int has_suffix(const char *str, const char *suffix) {
  size_t len = strlen(str);
  size_t slen = strlen(suffix);
  return (len >= slen && !memcmp(str + len - slen, suffix, slen));
}

/* Dynamic buffer package */

static void *dbuf_default_realloc(void *opaque, void *ptr, size_t size,
                                  int alloc_tag = 0) {
  return realloc(ptr, size);
}

void dbuf_init2(DynBuf *s, void *opaque, DynBufReallocFunc *realloc_func) {
  memset(s, 0, sizeof(*s));
  if (!realloc_func) realloc_func = dbuf_default_realloc;
  s->opaque = opaque;
  s->realloc_func = realloc_func;
}

void dbuf_init(DynBuf *s) { dbuf_init2(s, NULL, NULL); }

/* return < 0 if error */
int dbuf_realloc(DynBuf *s, size_t new_size, int alloc_tag) {
  size_t size;
  uint8_t *new_buf;
  if (new_size > s->allocated_size) {
    if (s->error) return -1;
    size = s->allocated_size * 3;
    if (size > new_size) new_size = size;
    new_buf = static_cast<uint8_t *>(
        s->realloc_func(s->opaque, s->buf, new_size, alloc_tag));
    if (!new_buf) {
      s->error = TRUE;
      return -1;
    }
    s->buf = new_buf;
    s->allocated_size = new_size;
  }
  return 0;
}

int dbuf_write(DynBuf *s, size_t offset, const uint8_t *data, size_t len) {
  size_t end;
  end = offset + len;
  if (dbuf_realloc(s, end)) return -1;
  memcpy(s->buf + offset, data, len);
  if (end > s->size) s->size = end;
  return 0;
}

int dbuf_put(DynBuf *s, const uint8_t *data, size_t len) {
  if (unlikely((s->size + len) > s->allocated_size)) {
    if (dbuf_realloc(s, s->size + len)) return -1;
  }
  memcpy_no_ub(s->buf + s->size, data, len);
  s->size += len;
  return 0;
}

int dbuf_put_self(DynBuf *s, size_t offset, size_t len) {
  if (unlikely((s->size + len) > s->allocated_size)) {
    if (dbuf_realloc(s, s->size + len)) return -1;
  }
  memcpy(s->buf + s->size, s->buf + offset, len);
  s->size += len;
  return 0;
}

int dbuf_putc(DynBuf *s, uint8_t c) { return dbuf_put(s, &c, 1); }

int dbuf_putstr(DynBuf *s, const char *str) {
  return dbuf_put(s, (const uint8_t *)str, strlen(str));
}

int __attribute__((format(printf, 2, 3)))
dbuf_printf(DynBuf *s, const char *fmt, ...) {
  va_list ap;
  char buf[128];
  int len;

  va_start(ap, fmt);
  len = vsnprintf(buf, sizeof(buf), fmt, ap);
  va_end(ap);
  if (len < 0) return -1;
  if (len < sizeof(buf)) {
    /* fast case */
    return dbuf_put(s, (uint8_t *)buf, len);
  } else {
    if (dbuf_realloc(s, s->size + len + 1)) return -1;
    va_start(ap, fmt);
    vsnprintf((char *)(s->buf + s->size), s->allocated_size - s->size, fmt, ap);
    va_end(ap);
    s->size += len;
  }
  return 0;
}

void dbuf_free(DynBuf *s) {
  /* we test s->buf as a fail safe to avoid crashing if dbuf_free()
     is called twice */
  if (s->buf) {
    free(s->buf);
  }
  memset(s, 0, sizeof(*s));
}

/* Note: at most 31 bits are encoded. At most UTF8_CHAR_LEN_MAX bytes
   are output. */
int unicode_to_utf8(uint8_t *buf, unsigned int c) {
  uint8_t *q = buf;

  if (c < 0x80) {
    *q++ = c;
  } else {
    if (c < 0x800) {
      *q++ = (c >> 6) | 0xc0;
    } else {
      if (c < 0x10000) {
        *q++ = (c >> 12) | 0xe0;
      } else {
        if (c < 0x00200000) {
          *q++ = (c >> 18) | 0xf0;
        } else {
          if (c < 0x04000000) {
            *q++ = (c >> 24) | 0xf8;
          } else if (c < 0x80000000) {
            *q++ = (c >> 30) | 0xfc;
            *q++ = ((c >> 24) & 0x3f) | 0x80;
          } else {
            return 0;
          }
          *q++ = ((c >> 18) & 0x3f) | 0x80;
        }
        *q++ = ((c >> 12) & 0x3f) | 0x80;
      }
      *q++ = ((c >> 6) & 0x3f) | 0x80;
    }
    *q++ = (c & 0x3f) | 0x80;
  }
  return q - buf;
}

static const unsigned int utf8_min_code[5] = {
    0x80, 0x800, 0x10000, 0x00200000, 0x04000000,
};

static const unsigned char utf8_first_code_mask[5] = {
    0x1f, 0xf, 0x7, 0x3, 0x1,
};

/* return -1 if error. *pp is not updated in this case. max_len must
   be >= 1. The maximum length for a UTF8 byte sequence is 6 bytes. */
int unicode_from_utf8(const uint8_t *p, int max_len, const uint8_t **pp) {
  int l, c, b, i;

  c = *p++;
  if (c < 0x80) {
    *pp = p;
    return c;
  }
  switch (c) {
    case 0xc0 ... 0xdf:
      l = 1;
      break;
    case 0xe0 ... 0xef:
      l = 2;
      break;
    case 0xf0 ... 0xf7:
      l = 3;
      break;
    case 0xf8 ... 0xfb:
      l = 4;
      break;
    case 0xfc ... 0xfd:
      l = 5;
      break;
    default:
      return -1;
  }
  /* check that we have enough characters */
  if (l > (max_len - 1)) return -1;
  c &= utf8_first_code_mask[l - 1];
  for (i = 0; i < l; i++) {
    b = *p++;
    if (b < 0x80 || b >= 0xc0) return -1;
    c = (c << 6) | (b & 0x3f);
  }
  if (c < utf8_min_code[l - 1]) return -1;
  *pp = p;
  return c;
}

#if 0

#if defined(EMSCRIPTEN) || defined(__ANDROID__)

static void *rqsort_arg;
static int (*rqsort_cmp)(const void *, const void *, void *);

static int rqsort_cmp2(const void *p1, const void *p2)
{
    return rqsort_cmp(p1, p2, rqsort_arg);
}

/* not reentrant, but not needed with emscripten */
void rqsort(void *base, size_t nmemb, size_t size,
            int (*cmp)(const void *, const void *, void *),
            void *arg)
{
    rqsort_arg = arg;
    rqsort_cmp = cmp;
    qsort(base, nmemb, size, rqsort_cmp2);
}

#endif

#else

typedef void (*exchange_f)(void *a, void *b, size_t size);
typedef int (*cmp_f)(const void *, const void *, void *opaque);

static void exchange_bytes(void *a, void *b, size_t size) {
  uint8_t *ap = (uint8_t *)a;
  uint8_t *bp = (uint8_t *)b;

  while (size-- != 0) {
    uint8_t t = *ap;
    *ap++ = *bp;
    *bp++ = t;
  }
}

static void exchange_one_byte(void *a, void *b, size_t size) {
  uint8_t *ap = (uint8_t *)a;
  uint8_t *bp = (uint8_t *)b;
  uint8_t t = *ap;
  *ap = *bp;
  *bp = t;
}

static void exchange_int16s(void *a, void *b, size_t size) {
  uint16_t *ap = (uint16_t *)a;
  uint16_t *bp = (uint16_t *)b;

  for (size /= sizeof(uint16_t); size-- != 0;) {
    uint16_t t = *ap;
    *ap++ = *bp;
    *bp++ = t;
  }
}

static void exchange_one_int16(void *a, void *b, size_t size) {
  uint16_t *ap = (uint16_t *)a;
  uint16_t *bp = (uint16_t *)b;
  uint16_t t = *ap;
  *ap = *bp;
  *bp = t;
}

static void exchange_int32s(void *a, void *b, size_t size) {
  uint32_t *ap = (uint32_t *)a;
  uint32_t *bp = (uint32_t *)b;

  for (size /= sizeof(uint32_t); size-- != 0;) {
    uint32_t t = *ap;
    *ap++ = *bp;
    *bp++ = t;
  }
}

static void exchange_one_int32(void *a, void *b, size_t size) {
  uint32_t *ap = (uint32_t *)a;
  uint32_t *bp = (uint32_t *)b;
  uint32_t t = *ap;
  *ap = *bp;
  *bp = t;
}

static void exchange_int64s(void *a, void *b, size_t size) {
  uint64_t *ap = (uint64_t *)a;
  uint64_t *bp = (uint64_t *)b;

  for (size /= sizeof(uint64_t); size-- != 0;) {
    uint64_t t = *ap;
    *ap++ = *bp;
    *bp++ = t;
  }
}

static void exchange_one_int64(void *a, void *b, size_t size) {
  uint64_t *ap = (uint64_t *)a;
  uint64_t *bp = (uint64_t *)b;
  uint64_t t = *ap;
  *ap = *bp;
  *bp = t;
}

static void exchange_int128s(void *a, void *b, size_t size) {
  uint64_t *ap = (uint64_t *)a;
  uint64_t *bp = (uint64_t *)b;

  for (size /= sizeof(uint64_t) * 2; size-- != 0; ap += 2, bp += 2) {
    uint64_t t = ap[0];
    uint64_t u = ap[1];
    ap[0] = bp[0];
    ap[1] = bp[1];
    bp[0] = t;
    bp[1] = u;
  }
}

static void exchange_one_int128(void *a, void *b, size_t size) {
  uint64_t *ap = (uint64_t *)a;
  uint64_t *bp = (uint64_t *)b;
  uint64_t t = ap[0];
  uint64_t u = ap[1];
  ap[0] = bp[0];
  ap[1] = bp[1];
  bp[0] = t;
  bp[1] = u;
}

static inline exchange_f exchange_func(const void *base, size_t size) {
  switch (((uintptr_t)base | (uintptr_t)size) & 15) {
    case 0:
      if (size == sizeof(uint64_t) * 2)
        return exchange_one_int128;
      else
        return exchange_int128s;
    case 8:
      if (size == sizeof(uint64_t))
        return exchange_one_int64;
      else
        return exchange_int64s;
    case 4:
    case 12:
      if (size == sizeof(uint32_t))
        return exchange_one_int32;
      else
        return exchange_int32s;
    case 2:
    case 6:
    case 10:
    case 14:
      if (size == sizeof(uint16_t))
        return exchange_one_int16;
      else
        return exchange_int16s;
    default:
      if (size == 1)
        return exchange_one_byte;
      else
        return exchange_bytes;
  }
}

static void heapsortx(void *base, size_t nmemb, size_t size, cmp_f cmp,
                      void *opaque) {
  uint8_t *basep = (uint8_t *)base;
  size_t i, n, c, r;
  exchange_f swap = exchange_func(base, size);

  if (nmemb > 1) {
    i = (nmemb / 2) * size;
    n = nmemb * size;

    while (i > 0) {
      i -= size;
      for (r = i; (c = r * 2 + size) < n; r = c) {
        if (c < n - size && cmp(basep + c, basep + c + size, opaque) <= 0)
          c += size;
        if (cmp(basep + r, basep + c, opaque) > 0) break;
        swap(basep + r, basep + c, size);
      }
    }
    for (i = n - size; i > 0; i -= size) {
      swap(basep, basep + i, size);

      for (r = 0; (c = r * 2 + size) < i; r = c) {
        if (c < i - size && cmp(basep + c, basep + c + size, opaque) <= 0)
          c += size;
        if (cmp(basep + r, basep + c, opaque) > 0) break;
        swap(basep + r, basep + c, size);
      }
    }
  }
}

static inline void *med3(void *a, void *b, void *c, cmp_f cmp, void *opaque) {
  return cmp(a, b, opaque) < 0
             ? (cmp(b, c, opaque) < 0 ? b : (cmp(a, c, opaque) < 0 ? c : a))
             : (cmp(b, c, opaque) > 0 ? b : (cmp(a, c, opaque) < 0 ? a : c));
}

/* pointer based version with local stack and insertion sort threshhold */
void rqsort(void *base, size_t nmemb, size_t size, cmp_f cmp, void *opaque) {
  struct {
    uint8_t *base;
    size_t count;
    int depth;
  } stack[50], *sp = stack;
  uint8_t *ptr, *pi, *pj, *plt, *pgt, *top, *m;
  size_t m4, i, lt, gt, span, span2;
  int c, depth;
  exchange_f swap = exchange_func(base, size);
  exchange_f swap_block = exchange_func(base, size | 128);

  if (nmemb < 2 || size <= 0) return;

  sp->base = (uint8_t *)base;
  sp->count = nmemb;
  sp->depth = 0;
  sp++;

  while (sp > stack) {
    sp--;
    ptr = sp->base;
    nmemb = sp->count;
    depth = sp->depth;

    while (nmemb > 6) {
      if (++depth > 50) {
        /* depth check to ensure worst case logarithmic time */
        heapsortx(ptr, nmemb, size, cmp, opaque);
        nmemb = 0;
        break;
      }
      /* select median of 3 from 1/4, 1/2, 3/4 positions */
      /* should use median of 5 or 9? */
      m4 = (nmemb >> 2) * size;
      m = static_cast<uint8_t *>(
          med3(ptr + m4, ptr + 2 * m4, ptr + 3 * m4, cmp, opaque));
      swap(ptr, m, size); /* move the pivot to the start or the array */
      i = lt = 1;
      pi = plt = ptr + size;
      gt = nmemb;
      pj = pgt = top = ptr + nmemb * size;
      for (;;) {
        while (pi < pj && (c = cmp(ptr, pi, opaque)) >= 0) {
          if (c == 0) {
            swap(plt, pi, size);
            lt++;
            plt += size;
          }
          i++;
          pi += size;
        }
        while (pi < (pj -= size) && (c = cmp(ptr, pj, opaque)) <= 0) {
          if (c == 0) {
            gt--;
            pgt -= size;
            swap(pgt, pj, size);
          }
        }
        if (pi >= pj) break;
        swap(pi, pj, size);
        i++;
        pi += size;
      }
      /* array has 4 parts:
       * from 0 to lt excluded: elements identical to pivot
       * from lt to pi excluded: elements smaller than pivot
       * from pi to gt excluded: elements greater than pivot
       * from gt to n excluded: elements identical to pivot
       */
      /* move elements identical to pivot in the middle of the array: */
      /* swap values in ranges [0..lt[ and [i-lt..i[
         swapping the smallest span between lt and i-lt is sufficient
       */
      span = plt - ptr;
      span2 = pi - plt;
      plt = pi - span;
      lt = i - lt;
      if (span > span2) span = span2;
      swap_block(ptr, pi - span, span);
      /* swap values in ranges [gt..top[ and [i..top-(top-gt)[
         swapping the smallest span between top-gt and gt-i is sufficient
       */
      span = top - pgt;
      span2 = pgt - pi;
      pgt = top - span2;
      gt = nmemb - (gt - i);
      if (span > span2) span = span2;
      swap_block(pi, top - span, span);

      /* now array has 3 parts:
       * from 0 to lt excluded: elements smaller than pivot
       * from lt to gt excluded: elements identical to pivot
       * from gt to n excluded: elements greater than pivot
       */
      /* stack the larger segment and keep processing the smaller one
         to minimize stack use for pathological distributions */
      if (lt > nmemb - gt) {
        sp->base = ptr;
        sp->count = lt;
        sp->depth = depth;
        sp++;
        ptr = pgt;
        nmemb -= gt;
      } else {
        sp->base = pgt;
        sp->count = nmemb - gt;
        sp->depth = depth;
        sp++;
        nmemb = lt;
      }
    }
    /* Use insertion sort for small fragments */
    for (pi = ptr + size, top = ptr + nmemb * size; pi < top; pi += size) {
      for (pj = pi; pj > ptr && cmp(pj - size, pj, opaque) > 0; pj -= size)
        swap(pj, pj - size, size);
    }
  }
}

#endif

#pragma clang diagnostic pop
